The Prophet ﷺ ordered a man from the tribe of Bani Aslam to announce amongst the people that whoever had eaten should fast the rest of the day, and whoever had not eaten should continue his fast, as that day was the day of 'Ashura' .  

أَمَرَ النَّبِيُّ ﷺ رَجُلاً مِنْ أَسْلَمَ أَنْ أَذِّنْ فِي النَّاسِ أَنَّ مَنْ كَانَ أَكَلَ فَلْيَصُمْ بَقِيَّةَ يَوْمِهِ وَمَنْ لَمْ يَكُنْ أَكَلَ فَلْيَصُمْ فَإِنَّ الْيَوْمَ يَوْمُ عَاشُورَاءَ  

Messenger of Allah ﷺ said to a man from the tribe of Al-Aslam, "Proclaim among your people (or the people) on the day of 'Ashura' (tenth of Muharram), 'Whosoever has eaten anything should fast for the rest of the day; and whoever has not eaten anything, should complete his fast.' "  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ لِرَجُلٍ مِنْ أَسْلَمَ أَذِّنْ فِي قَوْمِكَ أَوْ فِي النَّاسِ يَوْمَ عَاشُورَاءَ أَنَّ مَنْ أَكَلَ فَلْيُتِمَّ بَقِيَّةَ يَوْمِهِ وَمَنْ لَمْ يَكُنْ أَكَلَ فَلْيَصُمْ  

Salama b. al-Akwa' (Allah be pleased with him) reported that the Messenger of Allah ﷺ sent a person of the tribe of Aslam on the day of 'Ashura and commanded him to declare to the people to observe fast in case they had not observed it, and to complete fast till evening if they had taken food  

أَنَّهُ قَالَ بَعَثَ رَسُولُ اللَّهِ ﷺ رَجُلاً مِنْ أَسْلَمَ يَوْمَ عَاشُورَاءَ فَأَمَرَهُ أَنْ يُؤَذِّنَ فِي النَّاسِ مَنْ كَانَ لَمْ يَصُمْ فَلْيَصُمْ وَمَنْ كَانَ أَكَلَ فَلْيُتِمَّ صِيَامَهُ إِلَى اللَّيْلِ  

"Salamah told us that the Messenger of Allah said to a man: 'Announce the day of Ashura. Whoever has eaten let him not eat for the rest of the day, and whoever has not eaten, let him fast."'  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ لِرَجُلٍ أَذِّنْ يَوْمَ عَاشُورَاءَ مَنْ كَانَ أَكَلَ فَلْيُتِمَّ بَقِيَّةَ يَوْمِهِ وَمَنْ لَمْ يَكُنْ أَكَلَ فَلْيَصُمْ  

[Machine] "That the Messenger of Allah ﷺ said on the day of Ashura, 'O people, whoever among you wishes to fast this day may do so, and whoever does not wish to fast, let him complete his fast. And whoever eats, let him continue his fast for the rest of the day.'"  

أَنَّ رَسُولَ اللهِ ﷺ قَالَ يَوْمَ عَاشُورَاءَ «يَا أَيُّهَا النَّاسُ مَنْ كَانَ مِنْكُمْ يُرِيدُ أَنْ يَصُومَ هَذَا الْيَوْمَ فَلْيَصُمْهُ وَمَنْ لَمْ يَكُنْ أَكَلَ فَلْيُتِمَّ صَوْمَهُ وَمَنْ أَكَلَ فَلْيَصُمْ بَقِيَّةَ يَوْمِهِ»  

[Machine] The Prophet ﷺ commanded his callers on the day of Ashura, "Whoever is fasting should continue their fast, and whoever has eaten and drank should complete their fast."  

أَنَّ النَّبِيَّ ﷺ أَمَرَ مُنَادِيَهُ فِي يَوْمِ عَاشُورَاءَ «مَنْ كَانَ صَائِمًا فَلْيَمْضِ فِي صَوْمِهِ وَمَنْ كَانَ أَكَلَ وَشَرِبَ فَلْيُتِمَّ صَوْمَهُ»  

[Machine] The Prophet ﷺ commanded the fasting of Ashura and said: "Whoever is fasting, let him complete his fast, and whoever is not fasting, let him complete the rest of his day."  

أَنَّ النَّبِيَّ ﷺ أَمَرَ بِصِيَامِ عَاشُورَاءَ فَقَالَ «مَنْ كَانَ صَائِمًا فَلْيُتِمَّ صَوْمَهُ وَمَنْ لَمْ يَكُنْ صَائِمًا فَلْيُتِمَّ بَقِيَّةَ يَوْمِهِ»  

The Prophet ﷺ ordered a man from the tribe of Bani Aslam to announce amongst the people that whoever had eaten should fast the rest of the day, and whoever had not eaten should continue his fast, as that day was the day of 'Ashura' . (Using translation from Bukhārī 2007)   

"أَذِّنْ في النَّاسِ: أَنَّ مَنْ كان أكَلَ فليَصُمْ بقيَّةَ يوْمِه، ومَنْ لم يكنْ أَكَلَ فليَصُمْ، فإِنَّ اليَوْمَ يومُ عاشُوراءَ".  

"أَمَر النَّبِىُّ ﷺ مُنَادِيَه فِى يَوْم عَاشُورَاءَ: مَنْ كَانَ صَائِمًا فَلْيَمْضِ فِى صوْمِهِ، وَمَنْ كَانَ أَكَلَ وَشَرِبَ فَلْيُتِمَّ صَوْمَهُ".